CA2217906C - Method for the concentration of liquid mixtures - Google Patents
Method for the concentration of liquid mixtures Download PDFInfo
- Publication number
- CA2217906C CA2217906C CA002217906A CA2217906A CA2217906C CA 2217906 C CA2217906 C CA 2217906C CA 002217906 A CA002217906 A CA 002217906A CA 2217906 A CA2217906 A CA 2217906A CA 2217906 C CA2217906 C CA 2217906C
- Authority
- CA
- Canada
- Prior art keywords
- liquid mixture
- turbo
- concentrator
- stream
- tubular body
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D1/00—Evaporating
- B01D1/22—Evaporating by bringing a thin layer of the liquid into contact with a heated surface
- B01D1/222—In rotating vessels; vessels with movable parts
- B01D1/228—In rotating vessels; vessels with movable parts horizontally placed cylindrical container or drum
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S159/00—Concentrating evaporators
- Y10S159/901—Promoting circulation
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
- Centrifugal Separators (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Supply And Distribution Of Alternating Current (AREA)
Abstract
The present invention relates to a method for the concentration of liquid mixtures, comprising the step of causing a continuous stream of the liquid mixtures to flow in the form of a turbulent thin layer in contact with a heated wall. For that purpose, a continuous stream of liquid mixture is fed into a turbo-concentrator comprising a cylindrical tubular body (1), a heating jacket (4) and a bladed rotor (8) rotatably supported in the cylindrical tubular body (1). The liquid mixture is centrifuged to form a dynamic and tubular thin layer, the thin layer advancing inside the cylindrical tubular body (1) then being discharged continuously in the form of a stream of concentrated liquid mixture.
Description
METHOD FOR THE CONCENTRATION OF LIQUID MIXTURES
DESCRIPTION
The present invention relates, in its more general aspect, to the concentration of substantially liquid mixtures and solutions.
More especially, the invention relates to a method for the industrial concentration of substantially liquid mixtures and solutions within all industrial sectors, such as, for example, the food sector, and in the disposal of urban refuse, in purification plants, and in the recovery of heavy metals contained in aqueous solutions, etc..
Purely for the sake of simplicity, these substantially liquid mixtures and solutions will be referred to in the course of the description as liquid mixtures.
The apparatuses chiefly used for the concentration of liquid mixtures include multiple-effect concentrators and vacuum concentrators.
The first type of technology comprises a series arrangement of two or more concentrators each comprising a container filled with the mixture to be concentrated, a coil heating device which is immersed in the liquid mixture and which is generally fed with steam, and finally a pipe system which connects in series the two or more containers constituting the plant. The liquid mixture in the first container is heated and concentrated by means of mains steam. After having reached a specific degree of concentration, the liquid mixture is conveyed into the next container where it is subjected to an analogous treatment, the only difference being that, in this case, the mains steam is replaced by the vapour coming from the first container, or that released from the liquid mixture in the first concentration stage. The process just described can be repeated several times until the desired concentration is obtained.
With this type of technology, however, it is possible to reach only a specific degree of concentration, which is determined by the viscosity of the product to be treated, because it is necessary to ensure that the product, which becomes gradually more dense, runs well from one container to another in the concentration plant in order to avoid undesired obstructions in the connecting pipe system. This problem is further aggravated if the liquid mixture to be treated contains various types of fibre, or aggregates of insoluble salts or the like. A further disadvantage presented by any type of liquid mixture to be treated, however, is that of the encrustations which form on the heating coils which have to be dismounted and cleaned periodically.
The second type of apparatus, the vacuum concentrators, normally comprise a container heated by a jacket or a heating coil, the latter being immersed in the liquid mixture to be treated, and a condenser for condensing the vapour formed in the concentration stage.
This type of apparatus, however, has the disadvantage of operating batchwise which, as is well known, limits productivity and requires more complex management operations . Added to this are the above-mentioned problems of the encrustations on the coils or other parts of the plant, and also a considerable waste of energy owing to the maintenance of reduced pressure in the plant.
The problem underlying the invention is to provide a method for the concentration of liquid mixtures of various kinds which avoids all the above-mentioned disadvantages.
DESCRIPTION
The present invention relates, in its more general aspect, to the concentration of substantially liquid mixtures and solutions.
More especially, the invention relates to a method for the industrial concentration of substantially liquid mixtures and solutions within all industrial sectors, such as, for example, the food sector, and in the disposal of urban refuse, in purification plants, and in the recovery of heavy metals contained in aqueous solutions, etc..
Purely for the sake of simplicity, these substantially liquid mixtures and solutions will be referred to in the course of the description as liquid mixtures.
The apparatuses chiefly used for the concentration of liquid mixtures include multiple-effect concentrators and vacuum concentrators.
The first type of technology comprises a series arrangement of two or more concentrators each comprising a container filled with the mixture to be concentrated, a coil heating device which is immersed in the liquid mixture and which is generally fed with steam, and finally a pipe system which connects in series the two or more containers constituting the plant. The liquid mixture in the first container is heated and concentrated by means of mains steam. After having reached a specific degree of concentration, the liquid mixture is conveyed into the next container where it is subjected to an analogous treatment, the only difference being that, in this case, the mains steam is replaced by the vapour coming from the first container, or that released from the liquid mixture in the first concentration stage. The process just described can be repeated several times until the desired concentration is obtained.
With this type of technology, however, it is possible to reach only a specific degree of concentration, which is determined by the viscosity of the product to be treated, because it is necessary to ensure that the product, which becomes gradually more dense, runs well from one container to another in the concentration plant in order to avoid undesired obstructions in the connecting pipe system. This problem is further aggravated if the liquid mixture to be treated contains various types of fibre, or aggregates of insoluble salts or the like. A further disadvantage presented by any type of liquid mixture to be treated, however, is that of the encrustations which form on the heating coils which have to be dismounted and cleaned periodically.
The second type of apparatus, the vacuum concentrators, normally comprise a container heated by a jacket or a heating coil, the latter being immersed in the liquid mixture to be treated, and a condenser for condensing the vapour formed in the concentration stage.
This type of apparatus, however, has the disadvantage of operating batchwise which, as is well known, limits productivity and requires more complex management operations . Added to this are the above-mentioned problems of the encrustations on the coils or other parts of the plant, and also a considerable waste of energy owing to the maintenance of reduced pressure in the plant.
The problem underlying the invention is to provide a method for the concentration of liquid mixtures of various kinds which avoids all the above-mentioned disadvantages.
The problem is solved, in accordance with the invention, by a method for the concentration of liquid mixtures, comprising the stage of causing a continuous stream of the liquid mixtures to flow in the form of a dynamic turbulent thin layer in contact with a heated wall.
The use of dynamic turbulent thin layers in contact with a heated wall has been found to be especially advantageous because it involves the formation of a large exchange surface, which substantially accelerates the processes of transporting mass and energy. Therefore, the use of thin layers enables the dimensions of the entire plant to be substantially reduced and the energy costs to be considerably decreased.
In a preferred embodiment of the present invention, a turbo-concentrator is used as the concentration unit. Of the machines of this type, that produced and marketed by the company VOMM-IMPIANTI E PROCESSI
of Milan (Italy) has been found to be especially useful and advantageous. This machine basically comprises a cylindrical tubular body, having a horizontal axis and closed at the opposite ends, which is provided with openings for the introduction of a liquid mixture to be treated and a stream of dry air travelling in the same direction, a heating jacket for heating the internal wall of the tubular body to a predetermined temperature, and a bladed rotor rotatably supported in the cylindrical tubular body where it is rotated at a circumferential speed variable from 30 to 50 m/s.
With the use of a turbo-concentrator of the above-mentioned type, the method of the invention is characterised in that it comprises the stages of:
- feeding a continuous stream of liquid mixture into the turbo-concentrator in which the bladed rotor is rotated at circumferential speeds variable from 30 to 50 m/s, - centrifuging the liquid mixture to form a dynamic and tubular thin layer in which the liquid mixture is maintained in a state of high turbulence by the blades of the bladed rotor, - advancing the dynamic and tubular thin layer to the discharge opening of the turbo-concentrator, causing it to flow substantially in contact with the heated wall of the latter to the discharge opening, - discharging continuously a stream of concentrated liquid mixture.
The use of the method just described, because it is continuous, permits much higher productivity than do the batch or semi-batch techniques of the prior art .
The use of an apparatus like that described above also substantially reduces the problems associated with the maintenance and the cleaning of the plant and thus the general management and production costs.
Advantageously, a stream of hot dry air is fed into the turbo-concentrator in the same direction as the stream of liquid mixture; thus, the speed at which vapour is removed is increased, which further reduces the residence times necessary for the stream in the concentration unit.
The above-mentioned stream of dry air preferably has a flow rate which may be up to 6 Nm3 of air per litre of evaporated water.
A further embodiment of the invention provides, where appropriate, for the recycling of a portion of the discharged concentrated stream upstream of the turbo-concentrator; this increases the viscosity of the incoming stream, which facilitates the operation of the concentrator.
The characteristics and advantages of the invention will become clear from the following description of embodiments of the method described above which is given with reference to an apparatus shown diagrammatically in the single appended drawing, which is provided purely by way of illustration.
Referring to the above-mentioned drawing,, an apparatus used for the method of concentration according to the invention comprises a turbo-concentrator formed basically by a cylindrical tubular body 1 which is closed at the opposite ends by bases 2, 3 and which is provided coaxially with a heating jacket 4 through which a fluid, for example diathermic oil, is to flow in order to maintain the internal wall of the body 1 at a predetermined temperature.
The tubular body 1 is provided with an opening S for the entry of the liquid mixture to be concentrated, an opening 6 for the stream of hot dry air, and also an opening 7 for the discharge of the concentrated liquid mixture.
A bladed rotor 8, the blades 9 of which are arranged helically and are orientated to centrifuge and simultaneously convey to the outlet the liquid mixture to be concentrated, is rotatably supported in the tubular body 1.
A motor M is provided to operate the bladed rotor at variable speeds.
The use of dynamic turbulent thin layers in contact with a heated wall has been found to be especially advantageous because it involves the formation of a large exchange surface, which substantially accelerates the processes of transporting mass and energy. Therefore, the use of thin layers enables the dimensions of the entire plant to be substantially reduced and the energy costs to be considerably decreased.
In a preferred embodiment of the present invention, a turbo-concentrator is used as the concentration unit. Of the machines of this type, that produced and marketed by the company VOMM-IMPIANTI E PROCESSI
of Milan (Italy) has been found to be especially useful and advantageous. This machine basically comprises a cylindrical tubular body, having a horizontal axis and closed at the opposite ends, which is provided with openings for the introduction of a liquid mixture to be treated and a stream of dry air travelling in the same direction, a heating jacket for heating the internal wall of the tubular body to a predetermined temperature, and a bladed rotor rotatably supported in the cylindrical tubular body where it is rotated at a circumferential speed variable from 30 to 50 m/s.
With the use of a turbo-concentrator of the above-mentioned type, the method of the invention is characterised in that it comprises the stages of:
- feeding a continuous stream of liquid mixture into the turbo-concentrator in which the bladed rotor is rotated at circumferential speeds variable from 30 to 50 m/s, - centrifuging the liquid mixture to form a dynamic and tubular thin layer in which the liquid mixture is maintained in a state of high turbulence by the blades of the bladed rotor, - advancing the dynamic and tubular thin layer to the discharge opening of the turbo-concentrator, causing it to flow substantially in contact with the heated wall of the latter to the discharge opening, - discharging continuously a stream of concentrated liquid mixture.
The use of the method just described, because it is continuous, permits much higher productivity than do the batch or semi-batch techniques of the prior art .
The use of an apparatus like that described above also substantially reduces the problems associated with the maintenance and the cleaning of the plant and thus the general management and production costs.
Advantageously, a stream of hot dry air is fed into the turbo-concentrator in the same direction as the stream of liquid mixture; thus, the speed at which vapour is removed is increased, which further reduces the residence times necessary for the stream in the concentration unit.
The above-mentioned stream of dry air preferably has a flow rate which may be up to 6 Nm3 of air per litre of evaporated water.
A further embodiment of the invention provides, where appropriate, for the recycling of a portion of the discharged concentrated stream upstream of the turbo-concentrator; this increases the viscosity of the incoming stream, which facilitates the operation of the concentrator.
The characteristics and advantages of the invention will become clear from the following description of embodiments of the method described above which is given with reference to an apparatus shown diagrammatically in the single appended drawing, which is provided purely by way of illustration.
Referring to the above-mentioned drawing,, an apparatus used for the method of concentration according to the invention comprises a turbo-concentrator formed basically by a cylindrical tubular body 1 which is closed at the opposite ends by bases 2, 3 and which is provided coaxially with a heating jacket 4 through which a fluid, for example diathermic oil, is to flow in order to maintain the internal wall of the body 1 at a predetermined temperature.
The tubular body 1 is provided with an opening S for the entry of the liquid mixture to be concentrated, an opening 6 for the stream of hot dry air, and also an opening 7 for the discharge of the concentrated liquid mixture.
A bladed rotor 8, the blades 9 of which are arranged helically and are orientated to centrifuge and simultaneously convey to the outlet the liquid mixture to be concentrated, is rotatably supported in the tubular body 1.
A motor M is provided to operate the bladed rotor at variable speeds.
A 35o solution of acetylated starch in acetic acid having a degree of acetylation equal to saturation was fed continuously into the turbo-concentrator described above at a flow rate of 100 kg/h. The internal wall of the turbo-concentrator was maintained at a temperature of 130°C. The bladed rotor, rotating at a circumferential speed of 40 m/s, centrifuged the liquid mixture against the wall of the turbo-concentrator where it formed a dynamic and turbulent tubular thin layer. After a residence time of 30 seconds, the stream of solution leaving the turbo-concentrator 1 was conveyed into a suitable storage unit (not shown). The solution so obtained had a concentration of 800.
A solution of polypropylene carbonate in methylene chloride, having a solids content of 20%, was fed continuously at a flow rate of 100 kg/h into the turbo-concentrator described above, in the same direction as a stream of hot dry air having a flow rate of 500 m3/h. The temperature of the internal wall of the turbo-concentrator was 120°C, the circumferential speed of the bladed rotor was 40 m/s and the residence time in the turbo-concentrator was 1 minute. The stream leaving the turbo-concentrator, having a 90% solids content, was then discharged in the form of a molten mass and conveyed to a suitable storage unit.
A 75% solution of sorbitol in water was fed into the turbo-concentrator at a flow rate of 100 kg/h. The temperature of the internal wall of the turbo-concentrator 1 was 140°C, the circumferential speed of the bladed rotor was 40 m/s, while the residence time in the turbo-concentrator 1 was 2 minutes. The concentrated stream leaving the turbo-concentrator exhibited a 99% solids content.
A saline solution of dump effluent as such or coming from a membrane concentration plant with an average solids content of 2% was fed into the turbo-concentrator at a flow rate of 1000 kg/h. The temperature of the internal wall of the turbo-concentrator 1 was 240°C, the circumferential speed of the bladed rotor was 40 m/s, while the residence time in the turbo-concentrator 1 was 2 minutes. The concentrated stream leaving the turbo-concentrator exhibited a 50o solids content.
A solution of polypropylene carbonate in methylene chloride, having a solids content of 20%, was fed continuously at a flow rate of 100 kg/h into the turbo-concentrator described above, in the same direction as a stream of hot dry air having a flow rate of 500 m3/h. The temperature of the internal wall of the turbo-concentrator was 120°C, the circumferential speed of the bladed rotor was 40 m/s and the residence time in the turbo-concentrator was 1 minute. The stream leaving the turbo-concentrator, having a 90% solids content, was then discharged in the form of a molten mass and conveyed to a suitable storage unit.
A 75% solution of sorbitol in water was fed into the turbo-concentrator at a flow rate of 100 kg/h. The temperature of the internal wall of the turbo-concentrator 1 was 140°C, the circumferential speed of the bladed rotor was 40 m/s, while the residence time in the turbo-concentrator 1 was 2 minutes. The concentrated stream leaving the turbo-concentrator exhibited a 99% solids content.
A saline solution of dump effluent as such or coming from a membrane concentration plant with an average solids content of 2% was fed into the turbo-concentrator at a flow rate of 1000 kg/h. The temperature of the internal wall of the turbo-concentrator 1 was 240°C, the circumferential speed of the bladed rotor was 40 m/s, while the residence time in the turbo-concentrator 1 was 2 minutes. The concentrated stream leaving the turbo-concentrator exhibited a 50o solids content.
Claims (3)
1. Method for concentration of liquid mixtures, comprising the steps of:
feeding a continuous stream of a liquid mixture into a turbo-concentrator comprising a cylindrical tubular body which has a hori-zontal axis and which is equipped with an opening for the introduction of the liquid mixture and with an opening for the discharge of the final product, a heating jacket for heating the internal wall of the tubular body to a predetermined temperature, and a bladed rotor rotatably supported in the cylindrical tubular body where it is rotated at cir-cumferential speeds variable from 30 to 50 m/s, centrifuging the liquid mixture to form a dynamic and tubular thin layer in which the liquid mixture is maintained in a state of high turbulence by blades of the bladed rotor, advancing the dynamic tubular thin layer to the discharge opening of the turbo-concen-trator, causing it to flow substantially in contact with the heated wall of the latter to the discharge opening, discharging continuously a stream of concentrated liquid mixture.
feeding a continuous stream of a liquid mixture into a turbo-concentrator comprising a cylindrical tubular body which has a hori-zontal axis and which is equipped with an opening for the introduction of the liquid mixture and with an opening for the discharge of the final product, a heating jacket for heating the internal wall of the tubular body to a predetermined temperature, and a bladed rotor rotatably supported in the cylindrical tubular body where it is rotated at cir-cumferential speeds variable from 30 to 50 m/s, centrifuging the liquid mixture to form a dynamic and tubular thin layer in which the liquid mixture is maintained in a state of high turbulence by blades of the bladed rotor, advancing the dynamic tubular thin layer to the discharge opening of the turbo-concen-trator, causing it to flow substantially in contact with the heated wall of the latter to the discharge opening, discharging continuously a stream of concentrated liquid mixture.
2. A method according to claim 1, wherein a stream of hot dry air is fed into the turbo-concentrator in the same direction as the continu-ous stream of liquid mixture.
3. A method according to any one of claims 1 and 2, wherein a portion of the continuous stream of concentrated liquid mixture leaving the turbo-concentrator is fed in again continuously upstream of the turbo-concentrator.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ITMI96A002091 | 1996-10-10 | ||
| IT96MI002091A IT1285493B1 (en) | 1996-10-10 | 1996-10-10 | METHOD FOR THE CONCENTRATION OF LIQUID MIXTURES |
| US08/948,157 US6146493A (en) | 1996-10-10 | 1997-10-09 | Method for the concentration of liquid mixtures |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2217906A1 CA2217906A1 (en) | 1998-04-10 |
| CA2217906C true CA2217906C (en) | 2006-12-05 |
Family
ID=26331433
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002217906A Expired - Lifetime CA2217906C (en) | 1996-10-10 | 1997-10-09 | Method for the concentration of liquid mixtures |
Country Status (8)
| Country | Link |
|---|---|
| US (2) | US6146493A (en) |
| EP (1) | EP0835679B1 (en) |
| AT (1) | ATE300344T1 (en) |
| BR (2) | BR9705396A (en) |
| CA (1) | CA2217906C (en) |
| DE (1) | DE69733795T2 (en) |
| ES (1) | ES2247614T3 (en) |
| IT (1) | IT1285493B1 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6027919A (en) | 1993-12-07 | 2000-02-22 | Genetics Institute, Inc. | BMP-12 and BMP-13 proteins and DNA encoding them |
| NL1008912C2 (en) | 1998-04-17 | 1999-10-19 | Dsm Nv | Method of drying melamine. |
| US20090324907A1 (en) * | 1999-07-08 | 2009-12-31 | D Amato Salvatore F | Tamper evident and resisting informational article and method of producing same |
| US20040253312A1 (en) * | 2001-09-28 | 2004-12-16 | Sowden Harry S. | Immediate release dosage form comprising shell having openings therein |
| KR100802340B1 (en) | 2006-05-11 | 2008-02-13 | 김태욱 | Evaporating Enrichment Equipment |
| ITMI20061846A1 (en) * | 2006-09-27 | 2008-03-28 | Geoline Srl | SYSTEM FOR THE SAFETY OF DRYING SYSTEMS OF ORGANIC SUBSTANCES SUFFICIENT TO CAUSE EPLOSIVE REACTIONS AND PROCEDURE FOR DRYING THESE SUBSTANCES |
| IT201900023046A1 (en) * | 2019-12-05 | 2021-06-05 | Vomm Impianti E Processi S P A | Product in the form of a powder comprising lactose and its production process |
| IT202000012517A1 (en) * | 2020-05-27 | 2021-11-27 | Vomm Impianti E Processi S P A | PROCEDURE FOR THE CONTINUOUS SANITIZATION OF WASTEWATER |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3357477A (en) * | 1966-12-23 | 1967-12-12 | Artisan Ind | Thin film processing apparatus |
| US3751010A (en) * | 1971-08-16 | 1973-08-07 | Monsanto Co | Mixer |
| US3985606A (en) * | 1974-08-02 | 1976-10-12 | Artisan Industries Inc. | Low-pressure deentrainment evaporator |
| DE3418982A1 (en) * | 1984-05-22 | 1985-11-28 | Vaclav Dipl.-Ing. 7500 Karlsruhe Feres | THICK FILM EVAPORATOR |
| US4894117A (en) * | 1988-04-28 | 1990-01-16 | Colgate-Palmolive Company | Process for manufacturing high bulk density particulate fabric softening synthetic anionic organic detergent compositions |
| US5028297A (en) * | 1989-01-27 | 1991-07-02 | Vestar, Inc. | Film-forming evaporation apparatus |
| DE4124337A1 (en) * | 1991-07-23 | 1993-01-28 | Rudolf Pelzer | THICK FILM EVAPORATOR |
| IT1252682B (en) * | 1991-11-13 | 1995-06-23 | Vomm Impianti & Processi Srl | PRODUCT IN HIGH SPECIFIC WEIGHT GRANULES, PARTICULARLY AS A POWDER DETERGENT ADDITIVE AND METHOD FOR ITS OBTAINING |
| ES2134919T3 (en) * | 1994-10-21 | 1999-10-16 | Vomm Impianti & Processi Srl | CONTINUOUS CHOCOLATE CONCHING METHOD. |
| EP0710670B1 (en) * | 1994-11-03 | 2000-06-14 | VOMM IMPIANTI E PROCESSI S.r.L. | A method of modifying starch |
| AT410747B (en) * | 1995-06-05 | 2003-07-25 | Kraft Foods Inc | METHOD FOR REDUCING THE VISCOSITY OF MELTED CHOCOLATE |
-
1996
- 1996-10-10 IT IT96MI002091A patent/IT1285493B1/en active IP Right Grant
-
1997
- 1997-10-06 EP EP97203081A patent/EP0835679B1/en not_active Expired - Lifetime
- 1997-10-06 AT AT97203081T patent/ATE300344T1/en not_active IP Right Cessation
- 1997-10-06 ES ES97203081T patent/ES2247614T3/en not_active Expired - Lifetime
- 1997-10-06 DE DE69733795T patent/DE69733795T2/en not_active Expired - Lifetime
- 1997-10-09 CA CA002217906A patent/CA2217906C/en not_active Expired - Lifetime
- 1997-10-09 US US08/948,157 patent/US6146493A/en not_active Expired - Lifetime
- 1997-10-10 BR BR9705396-1A patent/BR9705396A/en not_active IP Right Cessation
- 1997-10-10 BR BR9706396-7A patent/BR9706396A/en unknown
-
2000
- 2000-10-17 US US09/688,743 patent/US6837969B1/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| DE69733795D1 (en) | 2005-09-01 |
| US6837969B1 (en) | 2005-01-04 |
| ITMI962091A1 (en) | 1998-04-10 |
| ATE300344T1 (en) | 2005-08-15 |
| IT1285493B1 (en) | 1998-06-08 |
| US6146493A (en) | 2000-11-14 |
| ES2247614T3 (en) | 2006-03-01 |
| BR9705396A (en) | 2002-01-08 |
| BR9706396A (en) | 2000-05-09 |
| CA2217906A1 (en) | 1998-04-10 |
| EP0835679A1 (en) | 1998-04-15 |
| DE69733795T2 (en) | 2006-05-24 |
| EP0835679B1 (en) | 2005-07-27 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKEX | Expiry |
Effective date: 20171010 |